Biochip including side emitting-type light-emitting device and fabrication method thereof

ABSTRACT

The present disclosure a biochip including a side emitting-type light-emitting device, in which the bio-chip includes: a light-emitting device for emitting light from a fluorescent material; reflective layers provided over and under the light-emitting device so as to emit light from the sides of the light-emitting device; and reaction regions formed by etching of flanking regions of the light-emitting device. In the biochip, light emitted from the sides of the light-emitting device causes a biochemical reaction in the reaction regions. According to the present disclosure, light emitted from the light-emitting device moves only laterally without being transferred to the top or bottom of the bio-layer, and is transferred to the reaction regions formed by etching of flanking regions of the light-emitting device, so that a biochemical reaction in the reaction regions can be more efficiently performed.

BACKGROUND

1. Technical Field

The present disclosure relates to a biochip and a fabrication methodthereof, and more particularly, to a biochip including a sideemitting-type light-emitting device, in which light emitted from thesides of the light-emitting device included in a bio-layer can cause abiochemical reaction, and which can detect light emitted by thebiochemical reaction to thereby provide biochemical information, and toa method for fabricating the biochip.

2. Related Art

In general, a biochip is formed by arraying reference samples includingbiological molecules such as DNA and proteins on a substrate made of amaterial such as glass, silicon, a metal such as gold, or nylon.

The biochip basically uses biochemical reactions between the referencesample fixed to the substrate and a target material. Representativeexamples of the biochemical reaction between the reference sample andthe target sample include the complementary binding of DNA bases, and anantigen-antibody reaction.

Diagnoses using the biochip are generally performed by detecting thedegree of a biochemical reaction between the reference sample and thetarget sample through an optical process. An optical process that isgenerally used is based on fluorescence or luminescence.

FIG. 1 shows a cross-sectional view of a conventional chip having animage sensor.

Referring to FIG. 1, a biochip 100 having an image sensor comprises abio-layer 110, a filter layer 120 and an image sensor layer 130.

The bio-layer 110 is a layer in which a biochemical reaction between areference sample and a target sample takes place. In addition, as aresult of the biochemical reaction, a luminescent or fluorescentmaterial remains in the bio-layer 110.

In the case in which a luminescent material remains in the bio-layer110, it is required to block external light, because the luminescentmaterial itself emits light. However, in the case in which a fluorescentmaterial remains in the bio-layer 110, separate external light isrequired to emit light from the fluorescent material. Thus, in thiscase, a filter layer is required to block the external light from beingincident to the image sensor layer.

The filter layer 120 is formed under the bio-layer 110. The filter layerfunctions to block the external light from being incident to the imagesensor layer disposed under the filter layer, when a fluorescentmaterial remains as a result of the biochemical reaction.

In other words, the external light acts as noise in a process ofmeasuring the fluorescence of the fluorescent material by the imagesensor layer. Thus, the filter layer functions to remove the externallight that is noise.

The image sensor layer 130 is formed under the filter layer 120, andcomprises a plurality of photodetectors 131. The plurality ofphotodetectors 131 functions to detect the light filtered by the filterlayer and to convert the detected light into an electrical signal.

However, the conventional biochip 100 as described above hasshortcomings in that the difference between the wavelength (λ₁) of theexternal light and the wavelength (λ₂) of light emitted from theluminescent or fluorescent material is very small and in that it isrequired to design a precise filter layer 120 capable of filtering outlight corresponding to this small difference.

SUMMARY

Various embodiments are directed to a biochip including a sideemitting-type light-emitting device, in which the bio-chip includes: alight-emitting device comprising a light-emitting region for emittinglight from a fluorescent material, and reflective layers provided overand under the light-emitting region so as to emit light from the sidesof the light-emitting device; and reaction regions formed by etching offlanking regions of the light-emitting device so that light emitted fromthe sides of the light-emitting device will cause a biochemical reactionin the reaction regions.

Also, various embodiments are directed to a method for fabricating abiochip including a side emitting-type light-emitting device, which isconfigured such that light emitted from the sides of the light-emittingdevice causes a biochemical reaction in reaction regions.

In an embodiment, a biochip including a side emitting-typelight-emitting device includes: a bio-layer having formed therein aplurality of reaction regions in which a biochemical reaction between areference sample and a target sample occurs; and an image sensor layerformed under the bio-layer and having formed therein a plurality ofphotodetectors, wherein the side emitting-type light-emitting device isdisposed in the bio-layer, and light emitted from the sides of the sideemitting-type light-emitting device is incident to the plurality ofreaction regions.

In another embodiment, a method for fabricating a biochip including aside emitting-type light-emitting device includes the steps of: (S100)forming an image sensor layer; (S200) forming a bio-layer; and (S300)depositing a bio-layer, wherein step (S200) of forming the bio-layerincludes the steps of: (S210) forming a light-emitting device layer; and(S220) forming reaction regions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a cross-sectional view of a conventional biochip having animage sensor.

FIG. 2 shows a cross-sectional view of a biochip including a sideemitting-type light-emitting device according to the present disclosure.

FIG. 3 is a process flowchart showing a method for fabricating a sideemitting-type light-emitting device according to the present disclosure.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments of the present disclosure will bedescribed in detail with reference to the accompanying drawings.

FIG. 2 shows a cross-sectional view of a biochip including a sideemitting-type light-emitting device according to the present disclosure.

Referring to FIG. 2, a biochip 200 including a side emitting-typelight-emitting device according to the present disclosure comprises abio-layer 210 and an image sensor layer 220.

The bio-layer 210 comprises a plurality of light-emitting devices 211and a plurality of reaction regions 212.

Each of the light-emitting devices 211 comprises a first reflectivelayer 211 a, a light-emitting region 211 b and a second reflective layer211 c.

The plurality of reaction regions 212 is formed by etching regionsexcluding regions in which the light-emitting devices 211 are formed inthe bio-layer 210, and is a place in which a biochemical reactionbetween a reference sample and a target sample occurs. The biochemicalreaction occurs when the target sample is added to the reaction regions212 containing the reference sample.

The reference sample is selected from various types of samples that areable to biochemically react with the target sample. The type ofreference sample varies depending on the type of biochemical reactionintended in the biochip. For example, if the biochemical reaction is anantigen-antibody reaction, the reference sample may be an antigen.

The type of target sample is determined according to the type ofreference sample. For example, if the reference sample is an antigen,the target ample may be blood or the like.

The light-emitting device 211 is connected with a peripheral circuitthat can emit light at a certain wavelength and that can control on-offswitching or the like. The light-emitting device 211 is preferably alight-emitting diode (LED) that emits light upon application of currentand that has excellent light emission efficiency.

Herein, the first reflective layer 211 a is positioned under thelight-emitting region 211 b, and the second reflective layer 211 c ispositioned over the light-emitting region 211 b. The first reflectivelayer 211 a and the second reflective layer 211 c functions as ablocking layer that allows light emitted from the light-emitting region211 b to be directed to the side without being directed upward anddownward.

Due to these reflective layers, light emitted from the light-emittingdevice 211 is not incident to the top and bottom of the bio-layer 210.In other words, the emitted light is not incident to the image sensorlayer 220, but is directed only to the plurality of reaction regions 212formed at the sides of the light-emitting devices 211.

Meanwhile, no reflective layer is formed over the light-emitting device,if required, so that light emitted from the light-emitting device can beincident to the top of the bio-layer 210.

Although not shown in the figures, a filter layer for blocking lightemitted from the light-emitting device 211 may further be formed betweenthe bio-layer 210 and the image sensor layer 220. The filter layertogether with the first reflective layer 211 a functions to block lightemitted from the light-emitting region 211 b from being incident to theimage sensor layer 220 and to allow only fluorescent light, generated bya biochemical reaction in the reaction region 212, to be incident to theimage sensor layer. The image sensor layer 220 is formed under thebio-layer 210 and comprises a plurality of photodetectors 221.

The plurality of photodetectors 221 is formed on the surface of theimage sensor layer 220 and functions to detect light and to produce acharge corresponding to the detected light. To each of the plurality ofphotodetectors 221, a peripheral circuit for producing an electricalsignal based on the produced charge is connected. Typical examples ofthe plurality of photodetectors 221 include charge-coupled device

(CCD) type image sensors and complementary MOS (CMOS) type imagesensors.

The plurality of reaction regions 212 is formed by an etching process onbio-layer regions in which the light-emitting devices 211 are notformed. The etching process may be performed using various methods suchas wet etching or dry etching.

Meanwhile, the reaction regions that are formed by etching may havevarious shapes. Specifically, the reaction regions may be formed using aconventional method such as slope etching so as to have a slanted shape,or may be formed by a multi-step etching process so as to have a steppedportion.

FIG. 3 is a process flow chart showing a method for fabricating abiochip including a side emitting-type light-emitting device accordingto the present disclosure.

Referring to FIG. 3, a method for fabricating a biochip including a sideemitting-type light-emitting device according to the present disclosurecomprises the steps of: (S100) forming an image sensor layer; (S200)forming a bio-layer; and (S300) depositing the bio-layer.

In step (S100) of forming an image sensor layer, an image sensor layercomprising a plurality of photodetectors is formed on a semiconductorsubstrate, and in step (S200) of forming a bio-layer, a bio-layer,comprising side emitting-type light-emitting devices and a plurality ofreaction regions, is formed on a substrate.

Step (S200) of forming the bio-layer comprises the steps of: (S210)forming a light-emitting device layer; and (S220) forming reactionregions.

In step (S210) of forming the light-emitting device layer, alight-emitting device layer having formed therein a plurality oflight-emitting devices, each comprising a reflective layer formed overand under a light-emitting region, is formed.

Specifically, a first reflective layer, a light-emitting region and asecond reflective layer are sequentially formed on the substrate,thereby forming a light-emitting device layer.

The first reflective layer and the second reflective layer may be madeof any material that prevents light emitted from the light-emittingdevice from being incident to the top or bottom of the bio-layer.

In step (S220) of forming reaction regions, a plurality of reactionregions is formed by dry- or wet-etching of flanking regions of thelight-emitting device layer portions in which the light-emitting regionswere formed.

Specifically, a plurality of reaction regions can be formed by etchingthe light-emitting device layer portions in which the light-emittingdevices were not formed, in such a manner that the reaction regions passthrough the second reflective layer and the first reflective layer.

Meanwhile, step (S220) of forming the reaction regions can be performedby dry or wet etching. In addition, step (S220) of forming the reactionregions can be performed by a multi-step etching process such that thereaction region has a plurality of stepped portions. Alternatively, step(S220) of forming the reaction regions can be performed by slope etchingsuch that the reaction region has a slanted shape.

Next, step (S300) of depositing the bio-layer is performed. In step(S300), the bio-layer is deposited on the image sensor layer, therebyfabricating the biochip including the side emitting-type light-emittingdevice according to the present disclosure.

After the step of forming the reaction regions, but before the step ofdepositing the bio-layer on the image sensor layer, the substrate may beremoved from the bio-layer so that a biochemical reaction occurring inthe reaction regions can be more accurately detected by the image sensorlayer.

Meanwhile, the method of the present disclosure may further comprise astep of forming a filter layer, which functions to block light emittedfrom the light-emitting device, between the bio-layer 210 and the imagesensor layer 220.

Herein, the filter layer may be formed on the image sensor layer in thestep of forming the image sensor layer.

Alternatively, the filter layer may be formed on the substrate in thestep of forming the bio-layer before the step of forming thelight-emitting device layer.

Specifically, the filter layer may be formed on the image sensor layer,and then the bio-layer may be deposited thereon. Alternatively, thefilter layer may be formed on the bottom surface, and then deposited onthe image sensor layer.

In the biochip including the side emitting-type light-emitting deviceaccording to the present disclosure, the reaction regions are not formedon the top surface of the bio-layer, but are formed so as to extend fromthe top to the bottom of the bio-layer, unlike the prior art. Thus,light emitted from the sides of the light-emitting devices will beincident to the plurality of reaction regions, and a biochemicalreaction between a reference sample and a target sample will occur inthe plurality of reaction regions.

Meanwhile, in the process of forming the plurality of reaction regionsby etching, the reaction regions can be formed to have various shapes.Specifically, the reaction regions can be formed using a conventionalmethod such as slope etching so as to have a slanted shape, or can beformed by a multi-step etching process so as to have stepped portions.

As described above, the biochip according to the present disclosureincludes the side emitting-type light-emitting devices provided in thebio-layer, and comprises the reaction regions formed to extend to thebottom of the bio-layer. Thus, light emitted from the side emitting-typelight-emitting devices is incident to the reaction regions to cause abiochemical reaction.

Light emitted from the side emitting-type light-emitting devicesaccording to the present disclosure is completely incident to thereaction regions formed at the sides of the light-emitting deviceswithout being incident to the top of the bio-layer or the image sensorlayer, so that a biochemical reaction between a reference sample and atarget sample in the region regions can more actively occur.

In other words, in the biochip including the side emitting-typelight-emitting device according to the present disclosure, light emittedfrom the light-emitting device moves only laterally without beingtransferred to the top or bottom of the bio-layer, and is transferred tothe reaction regions formed by etching of flanking regions of thelight-emitting device, so that a biochemical reaction in the reactionregions can be more efficiently performed.

While various embodiments have been described above, it will beunderstood to those skilled in the art that the embodiments describedare by way of example only. Accordingly, the disclosure described hereinshould not be limited based on the described embodiments.

What is claimed is:
 1. A biochip including a side emitting-typelight-emitting device, the biochip comprising: a bio-layer having formedtherein a plurality of reaction regions in which a biochemical reactionbetween a reference sample and a target sample occurs; and an imagesensor layer formed under the bio-layer and having formed therein aplurality of photodetectors, wherein the side emitting-typelight-emitting device is disposed in the bio-layer, and light emittedfrom sides of the side emitting-type light-emitting device is incidentto the plurality of reaction regions.
 2. The biochip of claim 1, whereinthe side emitting-type light-emitting device comprises: a firstreflective layer formed under a light-emitting region; and a secondreflective layer formed over the light-emitting region.
 3. The biochipof claim 2, wherein light from the side emitting-type light-emittingdevice is emitted from sides of the side emitting-type light-emittingdevice.
 4. The biochip of claim 1, wherein the plurality of reactionregions is formed by dry- or wet-etching so as to extend from top tobottom of the bio-layer.
 5. The biochip of claim 1, wherein theplurality of reaction regions is formed by a multi-step etching processso as to have a stepped portion.
 6. The biochip of claim 1, wherein theplurality of reaction regions is formed by slope etching so as to have aslanted shape.
 7. The biochip of claim 1, wherein the plurality ofreaction regions is formed by etching so as to have a rectangular orround shape.
 8. The biochip of claim 2, wherein the second reflectivelayer of the side emitting-type light-emitting device is partially orwholly open so that light from the side emitting-type light-emittingdevice is also emitted to the top of the bio-layer.
 9. The biochip ofclaim 1, further comprising a filter layer between the bio-layer and theimage sensor layer.
 10. A method for fabricating a biochip including aside emitting-type light-emitting device, the method comprising thesteps of: forming on a semiconductor substrate an image sensor layerhaving a plurality of photodetectors; forming a bio-layer having alight-emitting device and a plurality of reaction regions; anddepositing the bio-layer over the image sensor layer.
 11. The method ofclaim 10, wherein the step of forming the bio-layer comprises the stepsof: forming a light-emitting device layer having formed therein aplurality of the light-emitting devices, each having reflective layersover and under a light-emitting region; and forming the plurality ofreaction regions by etching light-emitting device layer portions inwhich the light-emitting devices were not formed.
 12. The method ofclaim 11, wherein the step of forming the light-emitting device layercomprises the steps of: forming a first reflective layer on a substrate;forming on portions of the first reflective layer a light-emitting layerhaving the light-emitting regions; and forming a second reflective layeron the light-emitting layer.
 13. The method of claim 12, wherein thestep of forming the reaction regions is a step of forming the reactionregions passing through the second reflective layer, the light-emittingdevice layer and the first reflective layer by dry- or wet-etching ofthe light-emitting device layer portions in which the light-emittingdevice was not formed.
 14. The method of claim 13, wherein the step offorming the reaction regions is a step of forming the reaction regionsby a multi-step etching process so as to have a stepped portion.
 15. Themethod of claim 13, wherein the step of forming the reaction regions isa step of forming the reaction regions by slope etching so as to have aslanted shape.
 16. The method of claim 13, further comprising, after thestep of forming the reaction regions, but before the step of depositingthe bio-layer on the image sensor layer, a step of removing thesubstrate from the bio-layer.
 17. The method of claim 10, wherein thestep of forming the image sensor layer further comprises a step offorming a filter layer on the image sensor layer.
 18. The method ofclaim 11, wherein the step of forming the bio-layer further comprises,before the step of forming the light-emitting device layer, a step offorming a filter layer on the substrate.
 19. The method of claim 18,wherein the step of depositing the bio-layer is a step of depositing thebio-layer in such a manner that the filter layer formed under thebio-layer is placed on the image sensor layer.